The invention relates to a modular system for drums for laundry care devices such as washing machines or driers. Drums serving to accommodate the laundry have the basic form of a hollow cylinder with a loading opening for loading and unloading the drum in the outer surface or in the front base plate.
Drums of this type have additional functional parts that are firmly attached to the drum or are formed therein. In conjunction with the drum or with other assemblies connected to the drum, the functional parts serve to intensify the washing or drying process, for example, as a component of the liquid flow system, the washing agent and additive dosing or the air inflow or outflow system.
Drums often have, as functional parts, a plurality of symmetrically arranged agitators which are attached to the inner wall of the drum casing or are formed into the drum casing. Agitators are used, in particular, to intensify the washing or drying process in that, on rotation of the drum, the laundry is lifted to a higher level, from which it then falls again. Agitators belonging to the prior art have a form which is similar in cross-section to symmetrical or asymmetrical triangles. The agitators used as single parts are usually made from plastics. Their attachment to the inner wall of the drum casing must be sufficiently secure, particularly in the case of washing machines, due to the not insignificant mechanical loads arising during operation. At the contact surfaces between the agitators and the drum casing, there must be no gaps into which laundry could penetrate and thereby become damaged.
In order to carry out particular washing functions, for example, to achieve a special scooping behavior with the aid of the agitators and to allow the scooped washing water to fall equally distributed or to impart a favored direction to the laundry as the drum rotates, several specially formed agitators which deviate from the usual orientation parallel to the axis and from the even triangular profile have been developed. DE 88 04 246 U1 discloses a screw-shaped curved agitator, by means of which the laundry is transported in the direction of the loading opening. This is intended to facilitate emptying of the laundry drum by the customer.
DE 199 25 917 A1 proposes, for a washing machine with a drum rotation axis which is inclined rising slightly toward the loading opening, an agitator which is arranged not parallel to the axis, but inclined to the direction of rotation. The aim is to impart to the laundry an additional movement component and to transport it forward to the loading opening. With this form of agitator and a matching arrangement of the scooping openings and of the washing water outlet openings, it is also achieved that the scooped washing water is lifted to a higher level and can fall evenly distributed over the laundry. This accelerates wetting of the laundry with washing water.
A three-part agitator especially configured for driers is disclosed in DE 38 43 705 C2. This known agitator comprises two similar carrier parts which, interlocked with one another, carry a measuring electrode which serves to detect the moisture content in the laundry. On assembly of the agitator, the measuring electrode, which consists of a bent sheet metal part is inserted into one of the carrier parts and then the other carrier part, is locked together with the first carrier part. The complete agitator is then screwed to the drum.
The agitators described have the disadvantage in common that the attachment thereof is no longer accessible after installation in the drum. From the standpoint of the production technology, this means, in disadvantageous manner, that the agitators must always be joined to the drum during preassembly. Therefore, if special agitators are to be used, a specially produced drum is always necessary. This has the consequence that for every alteration of the form or dimensions of the agitators, a correspondingly large number of different drums must be completely assembled and kept available for the final assembly.
For manufacturers with a wide assortment of models, this involves a substantially greater effort in production and particularly in storage, which makes the production of such devices not insignificantly more expensive. In the interests of more economical production, there is therefore a tendency among many manufacturers towards standardization, and this means that, for different device types, agitators with a uniform and neutral design, and therefore always the same effect in terms of washing technology, are used.
A similar principle applies to other functional parts attached to or molded into the drum.